在 Wikipedia 新增的帳戶將不能有 @ 這個字元在使用者名稱內，而已經存在的使用者如果有 @ 的用戶要記得去改名。
相關的資料可以在 [Announce-l] Wikizine - number: 45 看到：
New accounts on the WMF-wikis can not longer be created if the username contains the @-symbol. Existing users who have that symbol in there username can still login but only temporary. All these users need to request for a username change. Contact a local bureaucrat to do that or ask a steward if your wiki does not have a bureaucrat.
相關的 bug report 在 Bug 6849: Prevent usernames from using "@", which will stop people from using email addresses for usernames, a very common reason for blocking 這裡也可以看到。